The present invention is in the field of transducers, and more particularly, to transducers having a deformable diaphragm sensing element.
There are many forms of prior art transducers which incorporate a diaphragm member as the sensing element. Such sensing elements are also used in linear variable differential transformers (LVDT's) and other forms of motion transducers. In addition, certain forms of prior art strain gages use such diaphragms. In substantially all of these applications, the diaphragm sensing element is generally a relatively smooth, thin deformable member, often stretched between edge-located support points. While such diaphragms are generally effective in their intended uses, they are often the performance-limiting elements in the operation of sensors over temperature ranges, and also in sensitivity for such sensors. To achieve optimal performance, the diaphragm sensing element must be relatively stable dimensionally over temperature as well as provide a uniform sensitivity. In order to provide high sensitivity, the diaphragm must be very sensitive to deforming forces.
Generally, the prior art stretched diaphragms (such as thin sheets of stainless steel on the order of 0.0002 inches thick) are relatively limited in both sensitivity and stability.
Accordingly, it is an object of the present invention to provide an improved diaphragm sensing element for a transducer which is relatively stable while providing high sensitivity.
It is another object to provide an improved diaphragm which includes a portion which is resiliently displaceable along an axis perpendicular to that portion.